


The Butterfly Effect: Eating the Forbidden Fruit

by DragonPrincess101



Category: Gravity Falls, Kuroshitsuji | Black Butler
Genre: Adult Ciel Phantomhive, Attempted Murder, Awkward Dates, Ballroom Dancing, Bondage, Butterflies, Butterfly Effect, Child Ciel Phantomhive, Ciel Phantomhive Being an Asshole, Consensual Underage Sex, Corruption, Crossdressing, Crossdressing Kink, Crows, Dark Ciel Phantomhive, Demon Ciel Phantomhive, Demon Sex, Demon/Human Relationships, Demonic Possession, Denial of Feelings, Dresses, Dubious Consent, F/M, Falling In Love, Female Ciel Phantomhive, Forbidden Love, Hate to Love, Hurt/Comfort, I'm Sorry, Insanity, Jealousy, Lies, Limousine Sex, Lolita, Loss of Innocence, Love Potion/Spell, Love at First Sight, M/M, Manipulative Bill Cipher, Piano, Polyamory, Poor Ciel Phantomhive, Poor Dipper, Possessive Behavior, Self-Denial, Shame, Shapeshifting, Slow Dancing, Smut, Souls, Star-crossed, Taboo, Teenage Ciel Phantomhive, Tragic Romance, Underage Kissing, Violins
Language: English
Status: In-Progress
Published: 2016-03-27
Updated: 2016-03-29
Packaged: 2018-05-29 12:40:53
Rating: Mature
Warnings: Graphic Depictions Of Violence, Underage
Chapters: 3
Words: 2,212
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6375133
Author URL: https://archiveofourown.org/users/DragonPrincess101/pseuds/DragonPrincess101
Summary: <blockquote class="userstuff">
              <p>Since his transformation, Ciel felt so empty on the inside…centuries later, he and Sebastian went back to the human world out of boredom…</p><p>however the demon boy never knew that he’ll commit a great taboo all demons thread to commit for fear that it will be their ruin… fall in love with a human...</p><p>When Dipper sees this mysterious black-haired girl with a kind smile and single eye filled with sadness...he starts to fall for her yet he feels that the more they get close, the more he's falling apart but he can't help but to come back for more...</p>
            </blockquote>





	1. Love at First Sight

**Author's Note:**

> I don't own Black Butler or Gravity Falls
> 
> I get this inspiration from two Vocaloid's songs... 
> 
> Black Vow 
> 
> White Vow

… Hell was boring these days, so a pair of demon in their neo-victorian outfits named Ciel and Sebastian decided to return to the human world…They are currently in Gravity Falls, Oregon because they wish to see who will unfold the mysteries in this strange town…

“HA! LOOK AT THESE PAIR OF SISSY LOSERS IN THEIR FANCY GIRLY OUTFITS” shouted Robbie pointing at Ciel and Sebastian who are in their neo-Victorian outfits (the only style they are comfortable in so far).

The butler have a black leather tail-coat vest over a white frilly dress shirt with chain necklace, trousers and a pair of hooker heels and clawed leather gloves…The boy have a top hat with black roses and ribbons, black coat with white and black lace on his coat tail and sleeve edges, short trousers with garters attached knee-high stockings, heeled buckled shoes (not as high as Sebastian’s though), and he is holding a skull cane.

Wendy elbow shows Robbie’s arm, Tambry rolled eyes and keeps texting, Lee and Nate chuckled at the Ciel’s outfit until they sees Wendy’s glare, Thompson just stares in shock of Ciel’s unusual outfit.

“Sorry you have to hear him say that guys” said Wendy.

“That guy’s outfit is kinda hot… but that kid’s outfit is pretty weird though” she thought.

“Thank you for your apology madam” said Sebastian giving Wendy a bow.

Wendy smiles in surprise of the man’s manners and Robbie jealously glares at the butler.

“Well, Master we should continue our way” said Sebastian to Ciel who nods.

They continue on their path when…

“Master!? HAH! YOU HEAR THAT GUYS?! THAT MAN IS ACTING LIKE THIS KID’S BITCH!!!” laughed Robbie.

Sebastian and Ciel glares back at Robbie when Wendy punch Robbie’s arm.

“ROBBIE!” shouted Wendy.

“What?!” said Robbie rubbing his arm from the pain.

As the demons leave, Wendy feels a dark atmosphere from these “tourists”…

“ **Something is eerie about these two** …” muttered Wendy…

~~~

“It’s amazing that humans are starting become more and more ill-mannered in towns like this…” said Ciel.

Sebastian smirks when Ciel had address his former species as humans not people…meaning that he had fully accept his status as a demon…

“Well Master, as we both know humans had change over the years” said Sebastian.

“Well, I admit that they are some strange creatures around here…” asked Ciel.

“Yes Master, and soon you will be entertain when a human is brave enough to solve the mysteries” said Sebastian as he turns into a crow with red eyes.

Ciel smiles darkly and chuckles.

“Sure, I will indeed…” said Ciel as he turns into a blue butterfly.

Just when the demons arrive at the Mystery Shack, the ex-earl sees a pair of kids on a bench with a pig and a goat …Mabel was decorating Waddles while Dipper is reading the journal…

As soon as Ciel looks in the boy’s curious earth brown eyes, he feel this **strange feeling** he had never felt before but decides to ignore it… **at least for now…**

~~~

The Love God looks in his potions…

“Hey! What happened to the **Forbidden Love**? ” he said as he looks around…

~~~

A smiling man with yellow eyes is holding an empty bottle…The man had made a deal with Bill Cipher and after grant the man’s wish the dream demon uses his body to steal the potion…

“Oops…Oh dear! **Butterfly and Pine Tree** , you two will commit **a great taboo** …” laughed Bill as he throw the bottle away.


	2. Love in different forms

**Summary for the Chapter:**

> Ciel decides to meet Dipper in person after weeks of secretly protecting the lives of him and his loved ones...Dipper meets a mysterious girl

**Notes for the Chapter:**

> remember that Ciel and Sebastian have shapeshifting powers

Dipper is reading the journal on a bench with Mabel who playing with Waddles and unexpectedly a **blue butterfly** landed on a page...

“Wow! That’s the most beautiful butterfly I ever seen!” said Mabel walking there to see the butterfly up close.

Dipper feels something off about this insect… he never seen a butterfly like this around here… it could be a new species or a monster in disguise or something and for some reason Dipper feels a bit **fascinated** with this butterfly… **The insect** seems to stare at Dipper for a good 5 minutes and it crawl on his finger in time for Mabel to take a picture.

“And this is totally going to my scrapbook” giggled Mabel as she put the camera away.

The butterfly flew off as the twins’ watches it go.

“Why do I feel like **my soul was almost stolen**?” though Dipper confusedly.

~~~

The butterfly and crow are flying together over the town. They landed on the alley and changes back into their human form. They continue their path.

“Master, what do you find interesting about the boy?” asked Sebastian.

“Well, he had found a key to these mysteries of this town… the journal” said Ciel quickly.

The raven demon smiles and said “Anything else Master? You know you can tell me anything…”

The butterfly demon sighs “Well… you remember that I had said I felt hollow since I lose my humanity?”

Sebastian nods.

Ciel takes a deep breath “Well…”

~~~

Sebastian smiles and said "Master, you are saying that you love a human?"

Ciel scuffs and shook his head.

"Of course not! Why would I ever love a pathetic human" said Ciel as he crosses his arms.

"Master, I do know that _**love between a human and a demon only ends in tragedy**_ but remember that I'm eternally your loyal servant, there's no shame in telling the truth" said Sebastian with concern.

The butterfly demon rolled eyes shoos him off while closing his eyes.

"Just leave and do some errands, Sebastian that's an order!" said Ciel.

The raven demon bows lightly.

"Yes my lord" said Sebastian as he left Ciel to his thoughts

"Why do I feel this way around **a worthless human**?" thought the ex-earl.

~~~

_Some weeks later…_

Ciel feels a bit irritated whenever Dipper is around Wendy or when Pacifica get any close to Dipper...

"Humans are so ridiculous...Were normal humans always like this? ...He's lucky that his mysteries solving entertains me otherwise I would of let him die long ago..." thought Ciel.

"Master, did I smell envy?" said Sebastian smiling.

"No! it's that humans are very irritating when it comes to these relations...following their hearts when it often ends in tears! hah!" said Ciel as he folded his arms.

It's half true... but however, The demon butterfly is a bit jealous...but he reminds to believe that Dipper was useless...Suddenly Ciel smiles mischievously when an idea comes to his mind... **maybe he can have a bit of fun with that boy**...

~~~

_Next Day_

“You know Mabel, these crazy adventures we have… I’m amazed we made them out alive” said Dipper suspiciously as the twins were walking through the town.

“Well, maybe we have a **guardian angel** on our side” said Mabel as she skips.

“… **I’m not sure about that** ” muttered Dipper.

Suddenly he sees **a girl**  passing by carrying an umbrella and she seems to be close to his age. She have long bluish hair in curly pig tails with a tiny top hat, she's wearing a blue and black lolita dress with black gloves and heeled boots.

The girl turns around to see Dipper... He sees that she have an eyepatch, a shiny sapphire-like eye filled with sorrow, yet she is giving him a kind smile...

**Notes for the Chapter:**

> And the taboo begins
> 
> What ciel was wearing (I don't own it and you can look it up on deviantart) :  
> https://s-media-cache-ak0.pinimg.com/736x/b6/50/85/b65085aa52e7bbd940cad6426ca62c16.jpg


	3. Love is in the Air

**Summary for the Chapter:**

> Dipper and Cielle are hitting it off...

**Notes for the Chapter:**

> Maybe I'll put smut between Sebastian and Ciel next chapter

As the girl passes by Dipper, he caught a scent of _roses and tea._ She stops looking at Dipper and stays on the corner of the street as if she’s waiting for someone…

Mabel smiles when she sees Dipper staring at this girl.

“Oh gosh I love her outfit, go for her Dipper, you know you want to!” whispered Mabel excitedly as she elbowing him quickly but softly.

Dipper shrugs and walks towards the girl.

“Um, hi… I-I’m um never seen you around here before… are you visiting here too?” asked Dipper.

The girl looks at him with a bored face.

“Why yes, In fact I am vacationing here for the rest of the summer… my father and mother made my butler and I stay with my Aunt Angelia because they believed I need to be outdoors more often…It has been quite a boring week” she said.

Dipper notices that her accent is British and she sound so elegant.

“It’s not that bad,…well sometimes it is… but anyway my sister and I are on summer vacation too, we are staying with our great uncle I though it will be a boring summer and I’m telling you… a lot of **_interesting things_** has been happening in this town lately…” said Dipper smiling.

“For example?” said the girl softly.

“Um… well a lot of them are long stories and some are will probably sound just too crazy… but believe me there’s a lot of **weird things** here, and I think you’ll see soon enough” said Dipper smiling nervously.

“I see… and I understand… I have seen **some events** that people will believe I am insane if I were say a word about them…” she said as she darkly smiles.

Dipper felt a **dark aura** from her which frightens him yet he felt **allured** by it.

“The name is---” Dipper tells the girl his name to her when an ice cream truck passes which Mabel chases after.

“Ice cream!” shouted Mabel excitedly.

“But everyone calls me Dipper” said Dipper.

“I’m Lady Cielle Phantomhive of the Phantomhives…If you wish you can call me Cielle” she said.

They shake hands and Dipper felt that **_something is piercing his soul_** until they stop. Dipper notices that Cielle’s shiny blue eye is filled with **sorrow** the entire time… _What secret is she hiding?_

Cielle looks into her silver watch and looks at Dipper.

“My butler will be here in a few minutes… is there anything else you wish to tell me?” said Cielle lending to him seductively.

Dipper blushes and gulps.

“A-ah um, well my sister and I staying in the Mystery Shack just in that direction and the road on the left is the destination” said Dipper pointing at the direction.

Dipper suddenly sees a limo stop in front of them, a tall handsome man in a tailcoat suit with somewhat messy black hair comes out and opens the door for Cielle and he bows to her.

“My Mistress, it’s time for your discussion with your “aunt” ” said Sebastian.

“Very well Sebastian” said Cielle.

She takes out a notebook and a pen. She writes down, tear off the paper and gives it to Dipper.

“Well, thank you for your information…here is my phone number in case you wish to see me again” she said as she enters the limo.

Sebastian closes it and enters the limo.

The window rolls down and Cielle gives Dipper a smirk.

“I will see you soon, my dear Dipper” said Cielle seductively as the limo drives off.

Dipper smiles as he watches where the limo had left.

“Hey Dipper!” shouted Mabel.

Dipper snaps out of it and turns to Mabel whose is holding two ice cream cones.

“Hey where’d she go? I was going to give these two ice creams to you guys” said Mabel.

“She was in hurry, but she give me her number... and she smells like roses and tea” said Dipper showing Mabel the paper.

“Awesome! So where’s are you going date?” said Mabel excitedly.

“Aha, Mabel please I still kinda like Wendy” said Dipper as he laughs nervously.

“C’mon Dipper nothing’s wrong with keeping your “ **options** ” open! Everyone’s doing it!” said Mabel giving Dipper the ice cream.

Dipper gets it and looks down in regret.

“Oh… I’m just not sure if I should go through with **this** …I feel like I’m **doing a bad thing** ” said Dipper.

“C’mon Dipper **go with the flow** , it’s not like you’re in a relationship with Wendy anyway, so it’s not cheating” said Mabel as she stuffs the ice cream in her face.

Dipper sighs and shrugs.

“Fine, I’ll call her tonight” said Dipper.

Mabel’s eyes widen.

“Don’t call too quickly Dipper, you’re gonna sound too needy if you do… try tomorrow morning!” said Mabel excitedly.

~~~

Sebastian is driving the car and Cielle turns back into Ciel. The ex-earl then removes his eyepatch revealing his demonic eyes

“So master… How is he?” said Sebastian smiling calmly as his own demonic eyes are showing.

“He’s a typical pitiful human” said Ciel in annoyance.

“Hm, and yet for some reason he interested you doesn’t he?” said Sebastian smirking.

Ciel clinches his fist and nods admitting it to his butler.

“Well Master, shall I prepared you for your “ **first date** ”?” said Sebastian smiling.

"Right after your " **reward** " " said Ciel seductively lifting his dress showing off his fishnet stockings.

Sebastian smirks.

"In your new limo? My, my, you are becoming such **a bad boy** " said Sebastian.

"You know I am always **a bad boy** , Sebastian" said Ciel as he seductively detached the garters.

~~~

Back in the Mystery Shack, Ford’s eyes widen…

“Why am I feeling that something **forbidden**  is happening?” said Ford fearfully.

“Yeah, eating chilly dogs and ice cream at the same time will do that to your stomach” said Soos in pain.

Soos running away to the trashcan to puke. Ford and Stan make grossed out faces.

"Ah! You just cleaned that floor! WE WASTE ENOUGH WATER AS IT IS" said Stan.

**Notes for the Chapter:**

> if that last part ruins your mode... sorry
> 
> anyway next chapter is the date

**Author's Note:**

> So what do you think?
> 
> This idea just come to me a few days ago


End file.
